1. Field of the Invention
The present invention relates to a data terminal device that allows protection on copyrights with respect to obtained content data, particularly to a data terminal device that provides backup of content data inhibited of duplication in a recording medium. Furthermore, the present invention relates to a data terminal device that transfers obtained content data to another apparatus via a recording medium.
2. Description of the Background Art
By virtue of the progress in information communication networks and the like such as the Internet in these few years, each user can now easily access network information through individual-oriented terminals employing a cellular phone or the like.
By the recent incorporation of Java® into cellular phones, it is now possible to store various content data, image data for example, received from a server in the built-in memory of the cellular phone and provide the data on the display of the cellular phone. Also, game software can be received from a server at a cellular phone and stored in the built-in memory to be used to play that game through the cellar phone.
From the standpoint of copyright protection, the user cannot record such software stored in the built-in memory of a cellular phone to an external recording medium or transmit the same to another cellular phone. When the received software is no longer necessary, the user had to delete the software stored in the built-in memory from his/her cellular phone.
Even if the user wishes to store that software for later usage, that software had to be deleted if any new software is to be downloaded due to the limited size of the built-in memory of the cellular phone. The user has to receive the same deleted software from the server again to use that software afterwards.
Also, consider the case where the user changes his/her cellular phone. Since the software in the previously-used cellular phone cannot be transferred to the new cellular phone, the user must receive the same software from the server into the new cellular phone in order to use the same software in the new cellular phone.
This means that the user must pay again the fee required to receive the same software from the server. This is disadvantageous to the user.
There is also a problem that, in the case where a user wishes to give away a certain software program resident in his/her cellular phone to another user, the software could not be presented to the other user.